Pen point



P 1936- I c. PFANSTIEHL 2,053,407

PEN POINT Original Filed Sept. 1, 1934 Patented Sept. 8, 1936 UNITED STATES PATENT OFFICE PEN POINT Carl Pfanstiehl, Highland Park, 11]., assignor to Pfanstiehl Chemical Company, a corporation of Illinois.

6 Claims. (Cl. 219-15) This invention relates to pen-points and a method of preparing the same, and particularly to pen-points in which the tip and nib are integral.

In my Patent No. 2,005,752 is described a proc-- es of tacking and welding tips to pen nibs, and a method of forming integral tips upon pennib material.

The present invention is illustrated in the drawing, in which Fig. 1 represents an integrally formed pen-point having two spherical tips; Fig. 2 represents an integral pen-point having one spherical tip Fig. 3 is a broken elevation, partly in section,.of the fusing apparatus; Fig. 4 is an elevation of the pen-point holder, partly in seca copper holder l3 which is provided with a collar 26. After placing the pen-nib in the jaws I! it is placed within the fusing apparatus shown in Fig. 3. This apparatus comprises a tungsten filament 29, centrally located near the bottom of a Pyrex glass enclosed chamber 30, set in rubber gaskets 40. A hose 3| having outlets 32 is provided below the filament for the admission of a gentle stream of hydrogen or other ionizable gas. Hydrogen is preferred because of its tendency to prevent the formation of a metallic arc and because it provides a reducing atmosphere. The base of chamber 3| is divided by insulation 4| into portions 33 and 34. Filament 23 is set in copper terminals 35 and 38,

35 which-are electrically connected to a welding circuit which is more fully described in my co pending application Serial No. 706,565. A copper cover 31 is provided at the top otthe chamber 30, and is supplied with a central aperture I for the nib and holder to pass through. This opening is preferably substantially closed by the holder, but suflicient space is left for the gases to escape. Rising from the cover 31 is the neck 38, provided with copper cooling fins 33. Other cooling means may of course be substituted, for

example, water cooling means. The collar 26 of.

the holder l3 seats itself upon the shoulders 43 of the neck 38, and thereby establishes the proper distance between the tip II and the filament 29.

As shown in Fig. 4, the nib is held by the jaws I! a very short distance from the tip. Generally thisdistance willbefromi; to 1 ofaninch or less, but the distance depends upon the thickness of the nib and other factors which will be obvious to one skilled in the art. The cooling eilect of the jaws plus the connected cooling means on the neck is sufiicient to prevent any of the nib except that exposed from fusing, or even reaching a temperature which will draw the temper.

from the nib. The duration of the arc is preferably timed so that it will not continue unduly after formation of a spherical globule upon the tip of the nib.

Fig. 5 shows a preferred setting of the filament, although other arrangements may be used if desired.

The tungsten filament is continuously heated.

The are circuit comprises a 220 or volt A. C. supply which is stepped up by a transformer to 800-1000 volts. The tungsten filament is continuously heated by a high amperage low voltage current, for example, 30 amperes and 1 volts. The operation of the arc is controlled by a timing switch which may beset to cause an arc of any desired duration. With a hot tungsten filament and an ionized atmosphere of hydrogen and a gap of about between the hot filament and the pen nib, a time of the order of 1 to 2 seconds is satisfactory.

The hot filament ionizes the hydr en and thereby greatly lowers the resistance of the gap so that only 800-1000 volts is necessary to start the are with hydrogen. g

In carrying out the tip-forming operation, the pen-nib which has been placed in the jaws ll of the holder l3 with the tip of the nib exposed only 1;" or less beyond the end of the jaws'is placed within the fusing apparatus shown in Fig. 3. In the meantime the tungsten filament current has been started so that the filament is hot and a stream of hydrogen is passed gently through the chamber 30 and ionires as it passes the filament. The stream should be sufiiciently slow so that the atmosphere in the chamber is substantially quiescent. The switch then started. The operation of the arc heats the pin nib by heat received substantially entirely from below and the jaws of the holder l3 act as conductors to cool the remaining portions of the nib so that they do not fuse, nor is the temper thereof lost. For example, with a steel pen a substantially perfect sphere or globule of steel may be formed on the end of the pen, which may be readily split in the usual way. Substantially no buffing is required, but a perfectly smooth writing point is obtained.

Likewise an ordinary steel pen-nib may be formed to shape and split but the end not polished for writing. It may then be placed in the on each separate point of the pen.

When an air-hardening steel is used for the nib, the sudden heating and cooling produces the maximum hardness at the tip of the pen. Forthis purpose the use of a hydrogen atmosphere is beneficial in view of the fact that it con-.

ducts heat away much more rapidly than air.

Fig. 1 shows a steel pen l treated with its point split to produce a spheroidal globule it upon each tip. The treatment may be carried so far as to produce a substantially spherical globule, or it may be stopped somewhat short' of this when the tip is simply rounded or smoothed, in a somewhat similar fashion to the manner in which a rough piece of glass may be smoothed by heat. In either event, with a properly hardening steel, the tip itself is hardened to a degree which is not possible to the entire pen. I

The process may be used with other types of metallic pen-point material to produce; spherical'tips. I

In Fig. 2 is shown a point w with an integral single tip M which may be split in the customary manner.

' This application is a division of Serial No. 742,493, filed September 1, 1934 which was a dithe pen-nib is of air hardening steel.

' aoaaaor vision of application Serial Number 706,565 flied January 13, 1934.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should he understood 5 therefrom, but the appended claims should be construed as broadly as permissible, in view of the prior art.

What I claim as new and desire to secure by Letters Patent, is: v

1. The method of forming a tip upon a pen-' nib which comprises vertically suspending a pennib above an electric arc and fusing a tip of the nib by said arc to form a substantially spherical globule thereon, and cooling the globule to produce a spheroidally tipped nib, while maintaining the remainder of the nib substantially below fusion temperature.

2. The method as set forth in claim 1 in which 3. The method as set forth in claim 1 in which the pen-nib is of air hardening steel and the cooling is carried out in an atmosphere oi. hydrogen.

4. The method as set forth in claim 1 in which 25, one spheroid is formed upon the pen-nib and is subsequently split.

5. The method as set forth in claim 1 in which the pen-nib is split, the tips separated and globules formed on each by fusion, while they are so separated. v

6. The method as set forth in claim 1 in which the tip of the pen-nib is an electrode of the arc. 

